When flying above clouds on can frequently find
the shadow of the aircraft they are riding in. As the aircraft
approaches the cloud the observer will note a halo, known as a Glory, surrounding the shadow . If the
aircraft gets close enough to it's shadow one will see the Glory
is centered on the observer's position in the aircraft. I took
this phot from the cockpit of a 727 flying in and out of the
cloud tops on a flight from DCA to JFK. (1996)